1 files changed, 3 insertions, 1 deletions
diff --git a/src/pluginclass.c b/src/pluginclass.c
index 9997253..9125eed 100644
--- a/src/pluginclass.c
+++ b/src/pluginclass.c
@@ -34,7 +34,9 @@ slv2_plugin_class_new(SLV2World   world,
                       SLV2Node    uri,
                       const char* label)
 {
-	assert(!parent_node || librdf_node_is_resource(parent_node));
+	if (parent_node && sord_node_get_type(parent_node) != SORD_URI) {
+		return NULL;  // Not an LV2 plugin superclass (FIXME: discover properly)
+	}
 	SLV2PluginClass pc = (SLV2PluginClass)malloc(sizeof(struct _SLV2PluginClass));
 	pc->world      = world;
 	pc->uri        = slv2_value_new_from_node(world, uri);